A deadly severe-weather outbreak, including large hail, damaging straight-line winds and multiple strong tornadoes is underway across several states in the Plains and Midwest. Soon after a “Particularly Dangerous Situation” tornado watch was issued for northeastern Nebraska, a massive thunderstorm spawned at least two tornadoes at the same time near the small town of Pilger, Nebraska at about 4:20 p.m. CT, with reports of heavy damage in that area and at least one death. A nearby hospital in Norfolk, Nebraska reported that 16 people are also in critical condition from injuries sustained in the tornadoes.

Pilger has a population of about 350 people, according to the 2010 Census. Damage was also reported in Stanton, Nebraska, from that same storm.

Although rare, the phenomenon of simultaneous multiple tornadoes associated with the same severe thunderstorm is not unheard of. However, it is extremely rare for both tornadoes to be so intense and long-lasting. A more common phenomenon is to have so-called "satellite tornadoes" rotating around a main funnel, but in this case, it appears there were two independent, long-lived and powerful tornadoes about 1 to 2 miles apart.

Making this even more unusual, from a scientific standpoint, is that both tornadoes were spinning in the same direction.

Last Thursday, National Weather Service data from weather balloons, satellite imagery, radar data and computer models showed an extremely unstable atmosphere across portions of Nebraska, Iowa, South Dakota and Minnesota. The amount of wind shear — that is, winds varying in speed or direction (or both) with height — was off the charts, signaling the tornado threat.

The College World Series baseball tournament in Omaha, Nebraska could be threatened by the storms, which will track east to northeastward with time. Sioux City, Iowa is also threatened by damaging storms.

Check out some images and data of the ongoing storm, below. This is a developing story.

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